Heretofore, a color electrophotographic image forming apparatus for forming a multicolor image by an electrophotographic type is known. In the image forming apparatus the drum-shaped electrophotographic photosensitive member (photosensitive drum or drum) uniformly charged by a charging device is selectively exposed to form a latent image. The cartridges which contain the developers of the different colors are supported by a rotary member. The cartridge which contains the developer of the predetermined color is opposed relative to the photosensitive drum by a rotation of the rotary member to develop the latent image into a developed image. The developed image is transferred onto the recording material. The transfer operation of the developed image is carried out for each color. By this, the color image is formed on the recording material.
In a known structure, when the developing cartridge is detachably mounted to the main assembly, a rotational force is received from a main assembly using gears (Japanese Laid-open Patent Application 2007-241186).